信号码的一个刻划

A Characterizations of Semaphore Code

设X*是字母表X的自由幺半群,以X*为顶点集构造一个语言图Γ(X*),引入语言图Γ(X*)的模截集的概念。利用语言图Γ(X*)的模截集与极大前缀码的关系,即前缀码A是极大前缀码的充要条件是A是语言图Γ(X*)的模截集,给出了信号码的一个刻划。

Let X＇¤ be the free monoid on the alphabet set X.The concept of a transversal of the language diagramΓ（X＇） is introduced by constructing a language diagramΓ（X＇） withX＇ as the node set.Using the relation between the transversal of language diagram Γ（X＇） and maximal prefix code,i.e.a prefix code A is maximal if and only if A be a transversal of language diagram Γ（X＇）,a characterizations of semaphore code is given.